Friday, February 08, 2008

Rebuilding the 46rh, AKA the wimpy A518, Transmission

A year has gone by. So I suppose it's time for a new post on my "blog". Of course the quotes are supplied for the simple reason that a blog by the most meakest definition should contain an update once in a while. This one hasn't. But I aim to change that.

For the latest Nerdy Thing I Do I'm going to chronical the rebuilding of the Chrysler "slushmatic" 46rh transmission from my 1992 Dodge D250 pickup. The transmission recently took a dump...3rd gear refused to engage. I guess the Cummins finally took it's toll on it.

Being the "frugalista" that I am, I couldn't, with a good conscious, take my truck to a transmission shop to have it rebuilt. The cost is just too high. And, being the upgrades addict and constant tinkerer that I am, I decided to do it myself. This way I can have some upgrades for strength and durability and not break the bank. Of course, I really want to go all out on this project. But the funds, and the wife, just won't allow that. So I'm shooting for some middle-of-the-road position that will give some amount of strength for mild upgrades I've made to the Cummins.

So look here in the coming weeks for most posts, and pics of course, of how it's going and what I'm doing. Maybe it will help somebody along their own transmission journey.

And, to begin with, I'ld like to thank all the boys (and most likely a few girls) over at for all the help and adive they've given on the project. I literally couldn't have done it without them. Check it out. If you've got any year of Dodge with a Cummins diesel, the community there is friendly and extremely informative. Everyone on the forum, and especially the 1st genners (guys like me that own a Dodge Cummins between 1989-1993), and more than willing to pitch in their $.02.

More later.


Anonymous said...

Joel, excellent post. Thanks for it. I've got my 3rd!! 518 in my '93 W250 Crew Cab-the thing is having an issue upshifting into OD-I have to mash the gas pedal then let up and sometimes it will drop in-lately it hasn't done so. Should I adjust the bands? I don't know squat about these things either but I am a quick study.
Thanks again! Eric

Joel Jennings said...

Thanks Eric. For your issue I would guess there's a problem with the throttle position sensor which is mounted on top of the injection pump on the engine. It's basically a potentiometer that tells the computer how much fuel your giving the engine. It helps the computer determine when to engage the OD since it's an electrical shift. This is a well-known issue with these trucks, and a popular modification is to replace the TPS with a plain old $1.29 potentiometer that you can get at Radio Shack. You mount the potentiometer on your dash, and you can dial in a shift point for the OD. I've done this to mine, and I have it set to shift the OD at 35mph. When I'm towing my fifth wheel I dial it up to shift around 45mph. Let me know if you want more info on this. I did a write-up on it on It's a nice forum with lots of friendly people and lots of valuable information. You can always adjust the bands, but it won't help this problem :) I